Auto body shredder



Feb. H, 1969 A. A. TESTOLIN AUTO BODY SHREDDER Sheet Filed July 11, 1966 l'l-AMMEE ATTORNEYS Feb. 11, 1969 A. A.TESTOL|N 3,426,674

AUTO BODY SHREDDER Filed July ll, 1966 Sheet 3 of 2 III INVE NTO K HLFEO A. Tssroz. M/

M, M,ML

United States Patent 13 Claims ABSCT OF THE DISCLGSURE An auto body shredder for use with a hammer mill consists of an upper feeder roll provided with teeth which penetrate the auto body to feed it toward a shredder roll, the upper feeder roll being so located with respect to an underlying bed as to partially compress the auto body. The shredding roll is located lower than the feeder roll and is provided with shredding teeth having replaceable sharp-edged rectangular blocks at their front faces composed of hard material, the remainder of each tooth preferably tapering circumferentially rearwardly a substantial distance along the roll. The bed is provided with mating fixed teeth against which the teeth of the shredder roll Work which are also provided with hard replaceable blocks on their working faces, the blocks being preferably trapezoidal in horizontal cross section to define a cutting edge and a throat on the respective sides.

Background of the invention It has previously been known to feed automobiles into hammer mills, either whole, or compressed, or in pieces which have been sheared from the automobile body thereby compressing them as well as reducing their size. These procedures have serious disadvantages. Feeding large masses of metal into a hammer mill requires that the hammer mill have enormous power, on the order of several thousand horsepower. [Despite this great power, these masses of metal tend to jam the hammers of the hammer mill and render them ineffective, so'that' the hammer mill must frequently be stopped for service. The same is true of compressed masses of metal such as compressed car bodies, even if they have been sheared into smaller pieces. Moreover, the coiled or sinuous seat springs in an auto body have a marked tendency to jam the hammers in the mill, again requiring that the hammers be freed for effective operation.

The shears and compression devices of the prior art operate relatively slowly despite their great power. Using my device, the total horsepower required to run the preparation machinery and the hammer mill is greatly reduced, as compared with the horsepower required for prior art devices.

Both in the prior art devices and in my device, the ultimate objective is to reduce the auto body to a form in which it can be charged into a steel furnace. My device and the required hammer mill accomplish this end faster, using approximately one-third the horsepower required in prior art devices, and at the same time substantially reduce the need for stopping the hammer mill to free or replace the hammers. It is continuous, rather than intermittent, and lends itself to high production of scrap from auto bodies. The closest patents new known are Morgan 3,151,814; Sprague 3,143,304; and Mosley 3,049,274.

Drawings FIG. 1 is a vertical cross-sectional view on line 11 of FIG. 3.

FIG. 2 is an end view of my machine from the left end as shown in FIG. 1 with portions broken away.

FIG. 3 is a top view of my invention.

FIG. 4 is a view on line 44 of FIG. 1 showing the shredding roll of FIGS. 1 through 3.

FIG. 5 is a top view of a modified shredding roll of my invention.

FIG. 6 is a view on line 44 of FIG. 1, but showing the modified roll of FIG. 5.

Description of the invention The shredder of my invention consists of a bed 10 onto which auto bodies lacking axles and the other hard parts are fed by conveyor 11. Bed 10 is supported by members 12 and enclosed at the sides by side walls 13. Mounted on or adjacent to side walls 13 are bearings 14 which support a feed roll 20, and bearings 14a which support a shredder roll 30. Rolls 20 and 30 are respectively provided with shafts 15 and 15a which are driven by one or more motors 16 through reducing gears such as 17, 17a, 17b, 17c, and 17a. The motor, gears and bearings shown are merely illustrative, as many other practical arrangements are possible. For instance, separate motors and drive trains may be used for shafts 15 and 15a. The drives to rolls and are such that shredder roll 30 rotates at a much greater speed than feed roll 20.

Bed 10 is provided with a set of fixed teeth, referred to collectively as 40, which are adapted to interact with teeth on the shredder roll 30 to reduce fragments of the auto body being fed into my machine into convenient sized pieces for feeding to a hammer mill. Preferably an exit conveyor removes these pieces from the vicinity of the shredder roll, either to a storage location or preferably directly to the hammer mill, as shown in FIG. 1.

The feeder roll 20 of my invention preferably comprises a smooth cylindrical body mounted on shaft 15, and provided with feeder teeth 18 which desirably comprise axial series of cylindrical rods socketed in the roll 20 and secured in any conventional way against displacement. Because these rods project radially a substantial distance beyond the surface of roll 20 and have a sharp corner between the end and the side of the rod, they are well adapted to pierce the metal of the auto body or distort it in such a way as to obtain a firm purchase for feeding the auto body beneath the roll 20. Roll 20 is not sufficiently separated from bed 10 to admit an undistorted auto body. As the auto body is fed into my device, roll 20 reduces its height to substantially the distance between the periphery of roll 20 and bed 10. This may desirably be approximately one third to one half of the usual height of todays sedan auto bodies. -In any event, the lower margin of the periphery of roll 20 is approximately at or a little above the center line of shredder roll 30'.

Shredder roll 30, like feeder roll 20, has a cylindrical body which spans the distance between side walls 13. It is mounted sufficiently below feeder roll 20 so that teeth 31 approach very close to bed 10 as they approach their lowermost positions.

Each tooth 31 has a body 32 and a face block 33. The face 33 consists of a rectangular solid block of extremely hard material, such as a carbide, special steel or other material conventionally used for the cutting portions of tools. This block 33 is bolted or otherwise detachably secured to the face of body 32, so that upon wear of the face block 33 it may be inverted to provide a new working edge, or ground, or otherwise restored to the correct shape, and ultimately replaced as it becomes too Worn to be effectively restored to working condition. The body 32, as best shown at the right side of the shredder roll in FIG. 1, has a portion which is radially identical in extent with block 33. It then tapers in its radial dimension as it extends circumferentially rearwardly with respect to the direction of rotation of roll 30, to zero radial height at the rearmost portion 34 of body 32. The circumferential extent of each tooth 31 may desirably be more than twice the radial height of block 33. This great circumferential extent provides backing for block 33 and also provides a greatly elongated junction between tooth 31 and roll 30 along which the tooth body 32 may be welded. It has been found that generally rectangular teeth are apt to be severed from the roll at the weld line, because a tooth with short circumferential extent relative to its radial height will be subjected to large tension forces in the weld as the tooth tends to pivot about its rearward margin and lift at its forward margin. In my device, because of the circumferential length of tooth 31, the lever arm of the force tending to lift the tooth from the roll about a fulcrum at its rear margin is reduced greatly. Instead, the force is exerted in shear along the weld lines which join tooth 31 to roll 30. Because the force is in shear, and because the weld lines are very extensive in my tooth design, the tooth is far more durable than a short block welded to the roll would be. The exact shape of the tooth is not critical, although I prefer to taper or relieve the tooth rearwardly to avoid friction with the advancing car body 60. A short portion of the tooth near block 33 may have its outer surface concentric with the surface of roll 30.

As best shown in FIGS. 2 and 4, a number of distributions of teeth on the surface of roll 30 are practicable. For best results not more than one or two teeth should engage the car body 60 at a time. On the other hand, engagements should follow each other swiftly so that the body will be torn into relatively small pieces and so that there will be less impact shock on roll 30. As shown in FIG. 4 the teeth are placed in parallel lines which are at an angle to the axis of shaft a, and hence helical with respect to the surface of roll 30. Thus, if the tooth which is adjacent shaft 15a at the bottom of FIG. 4 is engaging the work, the next-to-the-last tooth in the next succeeding row at the upper end of FIG. -4 will also be engaging the work approximately simultaneously.

This configuration has one disadvantage, in that the impact forces of the teeth striking the auto body 60 will not necessarily be centered laterally with respect to the roll 30. For the best life of the various parts, particularly the bearings, it is desirable that these forces be balanced along the axis. Accordingly the preferred tooth pattern is that shown in FIGS. 2 and 3 in which the teeth of each row lie along helices of opposite pitch which intersect at the center of the roll to form a shallow V, with the lead tooth of each row in the center and the teeth on each side of the center tooth spaced backwardly along the circumference of the roll and axially from the center tooth an equal distance, so that teeth which are equal distances from respective bearings strike the work substantially simultaneously. Each succeeding pair of teeth is likewise on an axial line, with the two teeth spaced equally from the center tooth. Consequently either a single tooth in the center of the roll or two teeth spaced equally from the center of the roll will strike the work at a given instant, equalizing the load on the bearings as much as possible.

The row 40 of fixed teeth 41 on the bed 10 consists of generally rectangular blocks of tough steel having a very substantial length in the direction of travel of teeth 31. Teeth 41 are so related to teeth 31 as to have face contact with one side of a tooth 31 beginning as tooth 31 passes a vertically downwardly extending radius of roll 30. Each tooth 41 has a body 42 and a face block 43 made of hard material such as a carbide or other conventional material for cutting tools. In order to conserve such hard block material in block 43, and improve movement of metal scraps between teeth 41, the forward corners of teeth 41 which do not engage teeth 31 may be cut away at an angle so that block 43 has a trapezoidal top surface. This shape provides a throat through which the next tooth 31 may drag material which has been shredded from auto body 60, the throat serving as a die to compress the material. As best shown in FIGS. 5 and 6, at the side where tooth 31 has face contact with tooth 41 a shearing action occurs which limits the size of the pieces torn from the auto body.

The throat formed by tapering the forward edge of tooth 41 at one side has an additional effect in that when a tooth 31 strikes a seat spring, which is conventionally of sinuous or coiled steel wire, dragging the seat spring through the throat formed by the tapered corner at 44 has a marked tendency to pull the bends out of the seat spring. At the same time, the next adjacent tooth 31 will sever the spring. Thus the spring is reduced to a much more desirable form for feeding into the hammer mill, in that I have found that a relatively straight length of steel wire is much more likely to be reduced to small bits by the hammer mill than it is to jam the hammers.

In either shredder roll design there will be one raker tooth 35 (:which will either be at one end or in the center of each row) which will not have face contact with any tooth 41. These teeth merely straighten springs and drag material cut by adjacent teeth between teeth 41. If it proves desirable to have a cutting tooth rather than a raker tooth 35 at that point, it would be possible to design the teeth 41 at that point to have cutting edges, and face contact with teeth 31, at both sides of the face block 43, the teeth 31 being unchanged.

It will be noted that the design of my device is such that a steady stream of automobile bodies may be fed to it on conveyor 11 and reduced to small pieces which may be fed directly to a hammer mill by conveyor 50.

The word bed as used herein has reference to a lower portion which is of appropriate size and strength to receive a substantially complete automobile body and to withstand the loads imposed by the rolls acting on the car body, whether or not a conveyor is present. The words horizontal and vertical respectively mean the plane of the bed and a direction at right angles to the plane of the bed. The word below means a direction from the rolls toward the bed.

I claim:

1. An auto body shredder comprising a rotatable shredding roll provided with shredding teeth having generally radially extending leading working faces, a set of fixed teeth, each said fixed tooth having a working face positioned for shearing engagement with an edge of the working face of a said shredding tooth, a rota-table feeder roll spaced horizontally and vertically from the shredding roll and provided with generally radially extending means adapted to positively engage an auto body and feed it toward said shredding roll, and bed means below said feeder roll, said bed means and said feeder roll being spaced apart substantially less than the vertical height of an auto body whereby said feeder roll partially crushes said auto body while feeding it toward said shredder roll, the bottom of said feeder roll being positioned in a horizontal plane which extends close to the axis of said shredding roll.

2. :Ihe device of claim -1 in which each shredding tooth includes a tough body extending circumferentially rearw-ardly from the working face, the leading portion of said body having a radial height equal to that of the working face, said body declining in height to zero height at its re'armost portion, the dimension of said tooth circumferentially of said roll being at least twice the height of the working face, the entire circumference of said tough body being welded to said roll.

8. The device of claim 1 in which each shredding tooth is furnished with a detachable block of hard material on its working face.

4. The device of claim 1 in which each fixed tooth is provided with a detachable block of hard material on its working face.

5. The device of claim 1 in which each shredding tooth has shearing engagement with a fixed tooth on only one side.

6. The device of claim 1 in which said radially extending means on the feeder roll comprises feeder teeth consisting of sharp-cornered radially extending cylindrical pins.

7. The device of claim 1 in which one end of each fixed tooth has a shearing edge adapted for initial shearing contact with a shredding tooth, and a relieved edge at the same end of said fixed tooth to provide a throat through which a different shredding tooth is adapted to drag pieces from said body.

8. The device of claim 1 in which the shred-ding teeth are arranged in parallel helical series on the shredding roll.

9. The device of claim 1 in which the shredding teeth are arranged on the shredding roll in generally V-shaped rows, each row consisting of intersecting oppositely pitched helices.

10. The device of claim 1 in which said shredding roll is provided with raker teeth in addition to said shredding teeth, said raker teeth being disposed on said shredding roll to rotate free of shearing contact with said fixed teeth.

11. The device of claim 1 in which each shredding roll tooth and each fixed tooth is furnished with a detachable block of hard material secured .to the working face, each shredding roll tooth further comprising a tough body extending circumferentially rearwardly of said shredding roll from the detachable block, said body having a radial height equal to that of the block at the point of contact with the block and declining in height rearwardly to zero height, the dimension of each said shredding roll tooth circumferentially of said roll being at least approximately twice the height of the block, said tough body being welded to said roll around its circumference, each said shredding roll tooth having shearing engagement with a said fixed tooth along complementary edges of their respective working faces as the shredding roll tooth rotates past said fixed tooth, said block on said working face of each fixed tooth having a shearing edge adapted for initial shearing contact with a shredding roll tooth, and a relieved edge to provide a throat through which a different shredding roll tooth is adapted to drag pieces from said body, the radially extending means on said feeder roll each comprising a sharp-edged generally radially extending cylindrical pin.

12. An auto body shredder comprising a rotatable shredding roll provided with shredding teeth having generally radially extending leading working faces, a set of tfixed teeth, each said fixed tooth having a working face positioned for shearing engagement with an edge of the working face of a said shedding tooth, a rotatable feeder roll spaced horizontally and vertically from the shedding roll and provided with generally radially extending means adapted to positively engage an auto body and feed it toward said shredding roll, and bed means below said feeder roll, said bed m'eans and said feeder roll being spaced apart substantially less than the vertical height of an auto body whereby said feeder roll partially crushes said auto body while feeding it toward said shredder roll.

13. An auto body shredder comprising a rotatable shredding roll provided with shredding teeth having generally radially extending leading working faces, a set of fixed teeth, each said fixed tooth having a working face positioned for shearing engagement with an edge of the working face of a said shredding tooth, a rotatable feeder roll spaced horizontally and vertically from the shredding roll and provided with generally radially extending means adapted to positively engage an auto body and feed it toward said shredding roll, and bed means extending below said feeder roll and said shredding roll, said 'bed means and said feeder roll being spaced apart substantially less than the vertical height of an auto body whereby said feeder roll partially crushes said auto body while feeding it toward said shredder roll, a first conveyor means to feed auto bodies to one end of said bed means adjacent said feeder roll and a second conveyor means adjacent said shredding roll to carry material from said shredder, said first and second conveyor means and said bed means lying in a common horizontal plane, and said fixed teeth being positioned on said b'ed means beneath said shredding roller.

References Cited UNITED STATES PATENTS 1,656,063 1/ 1928 Harrison 94 2,150,984 3/1939 Near et al 241- 186 3,049,274 8/1962 Mosley IOU-98 XR 3,103,163 9/1963 G ates 100-98 3,143,304 8/1964 Spragg 2-41-186 3,151,814 10/ 1964 Morgan et a1 241-99 3,283,698 11/1966 Williams 100-95 FOREIGN PATENTS 4,7 47 3/1884 Great Britain.

BILLY J. WILHITE, Primary Examiner.

US. Cl. X.R. 241-186, 191 

